Abstract The influences of lower-level coherence in atomic medium of $\Xi$-type energy-level scheme on the absorption and dispersion are studied in dressed states. It is found that a weak probe light of a certain fre-quency can be free of atomic absorption, and at the same time has a large index of refraction.
Received: 11 May 1992
Accepted manuscript online:
PACS:
42.50.Nn
(Quantum optical phenomena in absorbing, amplifying, dispersive and conducting media; cooperative phenomena in quantum optical systems)
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